1. Field of the Invention
This invention relates to a hammer for sheet metal, particularly in auto body work, and more particularly, to a hammer wherein, a striking face of the hammer is revolved to exert a circumferentially sliding rotative force onto the face of the work sheet.
2. Prior Art
In sheet metal processing works, e.g., automobile body work, for example in the case of shaping a depressed portion of the outer sheet or plate of the automobile, the sheet can be falttened by placing a dolly in abutment against the inside of the depressed portion and hitting or striking out the depressed portion from the outside with a the hammer, with the outer plate being partially stretched or extended from its original dimension at the time the depression was created. Thus, even after the depression is struck out, the plastic deformation or elongation remains and protrudes sidewards of the sheet face to form a curved shape.
In order to remove this stretch, it is usual to heat and hit such a portion by a wooden hammer or the like and thereafter to cool the sheet metal.
Alternatively, in this striking process in which the work face is hit by the hammer, simultaneously with the hammer blow, the sliding of the hammer along the work face may also take up and relax stretch in the outer sheet.
However, this metal working requires very skilled labor who work by feeling and thus the result of the work may differ according to the technical ability of the worker.